Air filter



June 21, 1949. A. H. BAHNSON, JR 2,473,501

AIR FILTER Filed July 9, 1945 2 Sheets-Sheet 1 HITOENEKS.

June 21, 1949. A. BAHNSON, JR 2,473,501

AIR FILTER Filed July 9, 1945 2 Sheets-Sheet 2 Patented June 21, 1949 UNITED STATES PATENT OFFICE 7 Claims. 1

This invention relates to apparatus designed to clean the air of a weaving room. The apparatus will of course remove all sorts of suspended dust from air but, as stated, is particularly designed for operation in the atmosphere of a weaving room where the suspended dust includes lint and sizing material which tends to clog the air filter.

In a companion application Serial No. 593,988 I have disclosed an apparatus more particularly designed for filtering and cleaning the air of a spinning room, such air being substantially free of size and the like fine, non-fibrous dust.

In the present application I have illustrated a conventional apparatus designed to draw air from a room or space such as a weaving room or from the outer atmosphere or both and to add moisture to the air if desired and discharge it into the room or space the atmosphere of which is to be conditioned. By a sufiicient circulation of the air in the room it is kept sufiiciently clean and free from dust to avoid interference with the process (weaving) being carried on within the room.

It is of course possible to supply the room exclusively with air from the outside atmosphere which ordinarily is sufficiently clean that iiltering is unnecessary and to discharge an equal amount of dust laden air from the room and thus to keep the room atmosphere sufiiciently clean without filtering but practically all air conditioning systems require recirculation of air for economical operation and it is this recirculated air which must be filtered.

It is understood that the filter or air cleaner is shown in connection with an air circulating and humidifying duct merely for the purpose of illustration and that the air cleaner may be used in other relations.

Referring to the accompanying drawings:

Fig. 1 is a diagrammatic plan view of the air cleaner associated with an air circulating and humidifying duct;

Fig. 2 is an enlarged perspective view of the air cleaner;

Fig. 3 is a section on line 33 of Fig. 1;

Fig. 4a is a plan view of the air suction box and its connection the main humidifying duct;

Fig. 4b is a plan view of the dust box;

Fig. 4c is a plan view of the screen in the dust box and Fig. 5 is an enlarged front elevation with parts removed of the left hand end of the cleaner.

In Fig. 1, I is the ventilating duct open at the left hand end to the outer atmosphere, the right hand end extending into the room or space such as a weaving room in which the air is to be conditioned. The left hand end of the duct is controlled by dampers 2 which may be manually or automatically controlled to regulate the ratio of fresh and recirculated air supplied to the room. The operation of dampers 2 may be coordinated with the operation of dampers 3 which control the opening to the cleaner to determine the relative proportions of fresh and re-circulated air drawn into the duct. The operation of the damp ers 2 and 3 may be coordinated to the temperature or humidity or dust content of the air so as to maintain a predetermined condition. The duct may provided with means (not shown) for heating or cooling the air passing through it, and this heating or cooling means may of course be automatically controlled to maintain a predetermined temperature or relative humidity condition. is a fan driven by the motor 5 for propolling the air through the duct and may be controlled to operate at difierent speeds and its speed coordinated with the operation of the dampers 2 and 3 or automatically controlled with respect to the temperature or relative humidity of the air in the room. 6 is a revolving disc humidifier the driving motor of which is contained in the unit. Showing of the conduit for supplying water to be atomized and the means for regulating the amount thereof and the electric wires for operating the motor and the means for controlling the speed thereof are omitted since they are not involved in the present invention.

The cleaner 7 is a for-aminous cylinder formed, for instance, of coarse wire screen 8 supporting the cloth filter 9. The cylinder is closed at the left hand end as viewed in Figs. 2 and 4 and is open at the right hand end. It is mounted to rotate on the stationary shaft Ill and its open or right hand end is carried by the rollers II. It is driven or rotated by the motor [2 through speed reducing mechanism l3 and the drive pinion H l which engages the ring gear IE on the closed end of the cylinder.

The means for rotating the cylinder may be designed to rotate it continuously at a uniform rate or at a non-uniform rate corresponding to variations in the difference in pressure between the inside and the outside of the cylinder caused by the accumulation of dust on the filtering surface or interim tently, starting when the pressure difference attains a predetermined value and stopping when the pressure difierence falls below said predetermined value.

The open end of the cylinder is connected to the stationary transition member it, the joint being made relatively air tight by suitable flexible sealing flap (not shown) carried by the stationary transition member and engaging a smooth imperforate cylindrical ring at the end of the foraminous cylinder. Thus it will be seen that the fan 4 will create a suction in the ventilating duct to the left of the fan as viewed in Fig. 1, the suction serving to draw air through the filtering wall of the cylinder and through the open end of the cylinder and the transition member i6 and dampers 3 and any dust carried in suspension in the air will collect on the filtering surface.

In order to maintain the filter in continuous operation,,that is, in order to remove the accumulation of dust from the filter I provide the box 17 which has an open side shaped to fit the cylinder surface. The edges of the opening of the box may be sealed to the cylinder by flexible sealing flaps (not shown). The box IT has'a door 18 preferably provided. with a transparent portion or window i9 made of glass or transparent plastic such as Plexiglas "for observing the interior of the box. The box I! houses the rotary crush 20 which is rotated by the motor l2 through suitable gears 2| and engages the filter surface of the cylinder and removes accumulated dust therefrom which collects in the box I? below the brush. The dust deposited in the box can be removed manually from time to time through the door 13 or a suction pipe 22 may be provided as indicated in dotted lines in Fig. 3 for sucking the dust from the box and delivering it to a dump or other place of deposition (not shown).

The box i? also houses the stationary comb 23 which serves to prevent accumulation of lint in the brush 20 by engaging the brush as it rotates.

The brushing of the filter surface not only removes accumulated dust therefrom but causes.

some fine dust to pass through the filter. This is objectionable and I have provided means for preventing the dust which passes through the filter at the brushing from passing into the filtered air. For this purpose I have provided the suction box 29 which has an open slot adjacent the inner wall of the cylinder opposite the brush 20. The upper edge of the slot is sealed to the cylinder by the flexible sealing flap 25 and the lower edge is sealed to the cylinder by the brush 26 which also serves to loosen the dirt in the filter cloth and thus to prevent the filter cloth from becoming clogged with dust. The suction box 24 is connected at one end to the pipe 2'1 which extend through the transition member It to the filter box 28. Filter box 28 is connected into the conduit I and has a filter plate 29 interposed between the inlet of the pipe 27 and its outlet into the conduit i. It also has a cleanout opening closed by the removable cover 30. Suction within the conduit 5 is transmitted through the filter 29, the box 28 and pipe 27 to the suction box 2% and causes a flow of air which carries any dust forced through the filter 'l by the brush 29 to the filter 29.

It is to be noted that the filter cloth or the like 9 carried on the foraminous cylinder 8 is removable for cleaning or replacement. .In handling weaving room dust containing sizing material it may be desirable from time to time to remove and wash the filter cloth.

For completeness it is noted that the part marked 31 is a supporting frame which carries the left hand end of shaft [0 and also the box 57, motor i2 and its associated parts. The right hand end of the frame M is connected to the transition member 15. The right hand end of the shaft i9 is supported by the member 32 the ends of which are connected to the transition member 16. The radial arm 33 is supported by the shaft 10 and serves to support the suction box 24.

I claim:

1. An air filter comprising a filtering cylindrical wall mounted for rotation on its longitudinal axis, means for rotating the cylinder, means for sucking air inwardly through said cylindrical wall and with-drawing air from the interior of the cylinder, means for cleaning the cylindrical wall comprising a firstchamber. positioned outside the cylinder, said first fchamber having a slot embracing a portion of the cylindrical wall, means within said first chamber engagin said cylindrical wall through said slot for detaching accumulated filtered material from said surface; asecond chamberpositioned within said cylinder and having a slot embracing a portion of the inner surface of the cylindrical wall opposite said last named means; a stationary air filter connected to said second chamber and means for sucking air from said last named chamber through said stationary air filter.

2. An air filter as defined in claim 1 in which one edge of the slot of the second chamber is sealed to the inner surface of the cylinder bya brush.

3. An air filter as defined in claim 1 in which the means within the first chamber for cleaning the cylindrical wall comprises a rotatable brush and means for rotating the same.

4. An air filter as defined in claim 1 in which the means within the first chamber for cleaning the cylindrical wall comprises a rotatable brush and means for rotating the same and a stationary comb for cleaning the-brush.

5. An air filter as defined in claim 1 in which the first chamber is provided with a clean-out door having a transparent window.

6. An air filter as-defined in claim 1 in which the first chamber is connected to suction means for with-drawing accumulated dust therefrom.

'7. An air filter comprising a filtering cylindrical Wall mounted for-rotation, means for rotating the cylinder, means for drawing air to be filtered inwardly through said cylindrical wall and out of the cylindrical space within said wall through an end of the cylinder, the other end of the cylinder being closed, means for cleaning the -outersurface of the cylinder as it rotates comprising a chamber positioned adjacent the outside of the cylinder and having an open side embracing a portion of the cylindrical wall and means within said chamber engaging the cylindrical wall for removing accumulated filtered material therefrom, a second chamber within the cylinder having a slot embracing a portion of the inner surface of the cylindrical wall opposite said means engaging the outer surface and means for sucking air from the last named chamber.

AGNEW H. BAHNSON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED' STATES PATENTS 

